1. Field of the Invention
The invention relates to electroexplosive initiating devices and, more particularly, pertains to squibs useful for initiating the ignition or detonation of propellants, pyrotechnics, explosive materials, and the like.
2. State of the Art
Various means are known for initiating the detonation or ignition of energetic materials. Such initiating devices are variously known as initiators, blasting caps, detonation primers, headers, and squibs, depending upon the particular use. In each case, the initiating device comprises the first element in an igniter explosive train.
The electrical device initiating the explosive effect may be a hot wire bridge, a graphite bridge, a conductive mix of graphite and explosive material, a spark gap, an exploding bridge wire, a semiconductor bridge (SCB), or other means, all of which are known in the art.
Squibs are commonly used for initiating the firing of solid propellant rocket motors and gas generation devices such as automotive vehicle "air bag" safety devices. These squibs must therefore be extremely reliable even after years of exposure to extreme temperature variations, vibration, and other environmental factors.
The construction of prior art squibs is such that intimate contact between the initiating device and pyrotechnic material within the squib is not always ensured. In addition, the hermetic seal may disintegrate in time. Furthermore, fabrication of the squib is complex and costly.
There remains the need for a reliable squib which may be mass produced at low cost.